Coherent structure interactions in an unexcited coaxial jet

Shiu Keung Tang, N. W M Ko

Research output: Journal article publicationJournal articleAcademic researchpeer-review

14 Citations (Scopus)

Abstract

Based on a double triggering criterion, the axisymmetric and azimuthal structures within the initial region of an unexcited coaxial jet of mean velocity ratio of 0.3 (inner to outer) were recovered. Outer vortices, two trains of inner vortices and their amalgamation are found in the outer and inner mixing regions. Bifurcation of the amalgamated inner vortices occurs within the first two diameters of the jet and is responsible for the occurrence of the azimuthal structures in the inner jet region further downstream. Co-dominance of the symmetrical and azimuthal structures having different convection velocities is observed in the fully merged zone. Spatial separation between vortical structures and their relative vorticities are important parameters in affecting their convection velocities, growth and decay.
Original languageEnglish
Pages (from-to)147-157
Number of pages11
JournalExperiments in Fluids
Volume17
Issue number3
DOIs
Publication statusPublished - 1 Jul 1994
Externally publishedYes

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Computational Mechanics
  • Fluid Flow and Transfer Processes

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